POST TIME: Mark Messier’s guarantee turned into one of The Post’s most famous back pages when he backed it later that night with a hat trick against Martin Brodeur and the Devils.

It came out of the blue from the Blueshirts captain, Mark Messier’s guarantee the Rangers would win Game 6, which he fulfilled with a hat trick 18 years ago tonight in a performance that will live forever in Rangers lore.

Those Rangers were in disarray, the Presidents Trophy winners reeling by being pushed to the edge of elimination by two straight Devils victories in the 1994 Eastern Conference finals.

Star defenseman Brian Leetch and Messier had been benched in Game 4 by coach Mike Keenan, whose claim Leetch was injured was denied by Leetch. After they also lost Game 5, the Rangers needed a rallying point, and Messier provided an ultimate one.

These were the 1994 Rangers who had won their first league regular-season championship in 50 years in 1992, only to lose to the reigning Stanley Cup champion Penguins that spring. They were built precisely to end the 54-year Cup drought.

They massacred their main rivals at the time, the Islanders, 22-3, in a first-round sweep, and lost once to the Capitals in the second round. Then suddenly, the champs awaiting only coronation were in chaos, on the verge of ouster by the upstarts from the swamp and their yet-uncrowned Rookie of the Year goalie, Martin Brodeur.

That day, Messier strode into the locker room at the Rangers’ Rye Playland practice rink to meet the press, perhaps a dozen ink-stained wretches. As patchy memory serves, he stood in front of me and I asked, “What has to happen for this team to come back?”

Messier didn’t answer that insipid question directly.

Instead …

“We’re going to go in there and win Game 6,” Messier responded. “We know we’re going to go in and win Game 6 and bring it back for Game 7.”

It could have been anyone, in fact it might have been anyone asking, so disconnected were the question and the response. I believe the question could have been “What color is the sky today?” and Messier would have given the same answer.

That moment passed almost unnoticed as he handled more intelligent questions with more in-depth answers, but that quiet certainty, and his hat-trick fulfillment of it the next night, created a legend that still lives large in Rangers lore, and haunts the Devils.